Magazine and removable needle unit

ABSTRACT

A needle unit comprises a needle mounted in a hub having a sleeve made from a deformable material and surrounding an end of the needle at a radial distance from that needle. The sleeve is designed to be snap-locked onto a connecting piece at the outlet end of a syringe by protrusions on the inner wall of the sleeve engaging a circumferential recess in the outer wall of the connecting piece. It is also designed such that the locking engagement between the protrusions of this sleeve and the recess of the connecting piece is released when certain zones of the outer sleeve wall are pressed inwardly. A magazine for storing the needle unit comprises a compartment which can receive the needle unit in a plurality of rotational positions. The needle unit and magazine include a syringe/needle unit release mechanism which, in a first rotational position, does not press the release zones inwardly, thereby allowing the needle unit to lock onto the syringe, but which in a second rotational position, presses the release zones inwardly so that the needle disengages from the syringe and remains inside the magazine for disposal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 35 U.S.C. 371 national application ofPCT/DK95/00085 filed Feb. 27, 1995, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

The invention relates to needle units for disposable injection needles,and specifically a needle unit comprising a needle mounted in a hubhaving a sleeve made from a plastic material and surrounding an end ofthe needle in a distance from that needle, the unit being designed to bemounted at the outlet end of a syringe having a cylindric connectingpiece with a recess in a plane perpendicular to the cylinder axis, whichconnecting piece is received in the sleeve of the needle unit.

DESCRIPTION OF RELATED ART

By known needle units an inner surface of the depending sleeve isprovided with an inner thread corresponding to an outer thread on theconnecting piece of the syringe which the unit is intended for. The unitmay then be mounted on the syringe simply by screwing it onto theconnecting piece of the syringe.

However, such a screwing may be difficult to perform especially topeople with reduced tactile motor function, and particularly unscrewingof a used unprotected sharp needle may be difficult if the screwconnection has been carefully tightened when the unit was mounted.

Needle units are known of a type which can without screwing be mountedon a syringe which instead of a thread has a circumferential recess atthe inner end of its connecting piece. Such needle units have at theinner side of their depending sleeves protrusions engaging the recess ofthe receiving connecting piece of the syringe. This construction isknown from disposable syringes formed by snapping a needle unit onto theneck end of a cylinder ampoule, whereafter the syringe with the needleunit mounted is disposed of after use as a unity, as the needle unitcannot easily be demounted.

SUMMARY OF THE INVENTION

The object of the invention is to provide a needle unit of the snap-ontype, which may easily be snapped onto a durable pen type syringe andwhich may easily be dismounted from the syringe to make it possible tochange the needle without having to dispose of the syringe.

This is obtained by a needle unit of the above mentioned type, whichunit is characterized in that the sleeve is so designed that the lockingengagement between the protrusions of this sleeve and the recesses ofthe connecting piece is released when radial inward pressures areexerted on specific zones of the sleeve.

In an embodiment of the needle hub at least two protrusions may beprovided on the inner surface of the sleeve, the apexes of theseprotrusions lying on a circle having its centre in the axis of theneedle unit and having when the sleeve is not deformed a radius which issmaller than the radius of the connecting piece, and the connectingpiece may fit into the sleeve with a play allowing deformation of thesleeve to an extent enlarging the radius of the circle through theapexes of the protrusions to be at least equal to the radius of theconnecting piece.

The sleeve may either be deformed when the connecting piece is pressedinto the sleeve urging the protrusions to pass over the side wall ofthis connecting piece until they snap into the recesses in this wall, orthe deformation may be obtained by applying a radial inward pressures onthe outer side of the sleeve at zones circumferentially displaced fromthe position of the protrusions. By such radial pressures the sleevewill be deformed so that the protrusions will be drawn out of therecesses in the connecting piece.

To prevent the sleeve from wriggling on the connecting piece due to theplay between this sleeve and connecting piece, longitudinal spacer ribsmay be provided on the inner surface of the sleeve at positions lyingbetween the protrusions and zones lying halfway between the protrusions,which zones are designed for application of radial inward pressures.

Such spacer ribs are especially indispensable when according to theinvention only two protrusions are provided diametrically opposite eachother.

In another appropriate embodiment of the invention three protrusions areprovided 120° circumferentially spaced. To dismount this needle unit aninward pressure may be exerted at three zones of the periphery of thesleeve, which zones must be circumferentially displaced relative to thepoints bearing the protrusions.

As the inward protrusions are not visible from the outer side of thesleeve, the positions of the zones for application of radial inwardpressures may be indicated on the outer surface of the sleeve. Theindication of the zones may appropriately be protrusions on the outersurface of the sleeve. These outward protrusions may serve furtherpurposes as it will be described below.

The invention also concerns a magazine in which the needle unit may bestored. Such a magazine is characterized in that it comprises acompartment conforming the outer contour of the needle unit and havingan access opening. The walls of this compartment may be strengthenedagainst deformation and means for cooperation with the zones whereinradial inward pressures shall be exerted to release the hub may beprovided.

The means for cooperating with the said zones may be the edge of theaccess opening of the magazine or of an inner strengthening of thecompartment wall, which may be circular with outward recesses foraccommodation of outward protrusions at the pressure zones of the sleevewhen an unused needle unit is stored in the magazine, whereas engagementbetween the protrusions at the pressure zones of the needle unit andsaid edge will provide an inward pressure at said zones, when the unitis inserted in an empty magazine in a rotational position not bringingthe outward protrusions on the sleeve into the outward recesses of theaccess opening or the strengthening of the magazine.

In another embodiment ribs may be provided on an inner cylindric wall ofthe compartment. In this case the sleeve must be provided with recessesin its outer cylindric wall, which recesses may accommodate said ribswhen an unused needle unit is stored in the magazine. These recesses areprovided in the outer wall at the positions wherein the inwardprotrusions of the needle hub sleeve are provided and thereby indirectlyindicates the position of the pressure zones as the zones between tworecesses. When a needle unit is returned to a magazine in a rotationalposition wherein the ribs are not accommodated in the recesses, the ribswill exert a pressure on the zones lying between these recesses and willprovide the necessary deformation of the sleeve to release theengagement between the inward protrusions of the sleeve and the recessesof the connecting piece of the syringe.

The compartment wall is strengthened to be able to impart the necessarypressure to the zones without being deformed itself. This strengtheningmay be obtained by the access opening being surrounded by a flange. Thisflange and the compartment of the magazine may be one integral plasticmember.

The flange may appropriately be used as the support for a foil whichfixed to the flange covers the access opening and seals the compartment

BRIEF DESCRIPTION OF THE DRAWINGS

In the following a needle unit and a magazine according to the inventionwill be described in further details with references to the drawing,wherein

FIG. 1 shows a sectional view of a magazine with a needle unit accordingto the invention and a connecting piece for receiving the unit,

FIG. 2 shows schematically the needle unit in FIG. 1 rotated 90° andmounted on the connecting piece,

FIG. 3 shows the needle unit in FIGS. 1 and 2 seen from the open end ofthe sleeve,

FIG. 4 shows a sectional side view of the needle unit of FIGS. 1 to 3stored in a magazine,

FIG. 5 shows the magazine with the stored needle unit of FIG. 4 seenfrom the access end of the magazine,

FIG. 6 shows another embodiment of a needle unit seen from the open endof the sleeve,

FIG. 7 shows a sectional side view of the needle unit of FIG. 6 storedin a magazine,

FIG. 8 shows the magazine of FIG. 7 with the stored unit seen from theopen end of the magazine,

FIG. 9 shows still another embodiment of a needle unit seen from theopen end of the sleeve,

FIG. 10 shows a sectional side view of the needle unit of FIG. 9 storedin a magazine,

FIG. 11 shows the magazine of FIG. 10 with the stored needle unit seenfrom the open end of the magazine,

FIG. 12 shows a sectional side view of a magazine with a needle unitaccording to FIGS. 1-3 finally deposited in the magazine,

FIG. 13 shows the magazine and needle unit of FIG. 12 seen from theaccess opening of the magazine,

FIG. 14 shows a sectional side view of a magazine with the needle unitof FIG. 6 finally deposited in this magazine,

FIG. 15 shows the magazine of FIG. 14 seen from its open access end,

FIG. 16 shows a sectional side view of a magazine with the needle unitof FIG. 9 finally deposited in this magazine, and

FIG. 17 shows the magazine of FIG. 16 seen from its open access end.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a needle unit stored in a magazine. The needle unitcomprises a needle 1 mounted in a needle hub 2 which has a dependingsleeve 3 surrounding an end of the needle 1 in some distance from thisneedle. The depending sleeve 3 is designed to be received on a cylindricconnecting piece 4 of a syringe so that the surrounded part of theneedle penetrates a not shown rubber membrane forming at least a part ofan end surface 5 of the connecting piece 4.

At two diametrically opposite positions on the inner wall of the sleeve3 inward protrusions 6 are provided. The protrusions 6 are designed toengage a circumferential recess 7 in the connecting piece 4 receivingthe needle.

In FIG. 2 the needle unit has been rotated 90° and the receivingconnecting piece 4 has been inserted into the needle unit, and it isshown how the protrusions 6 engage the recesses 7 of the connectingpiece. The receiving connecting piece may be a closure part of acylinder ampoule and the recess may be provided at the neck part of suchan ampoule, but here the connecting piece is a part especially designedfor cooperation with a needle unit according to the invention.

The needle hub is manufactured of a plastic material which allow somedeformation of the sleeve 3 so that the diametrical distance between theapexes of the protrusions 6, which distance is smaller than the diameterof the connecting piece 4 when the sleeve is not deformed, may beincreased to allow the inward protrusions 6 to pass over the side wallof the connecting piece 4 until they can snap into the recess 7 when theconnecting piece 4 is pressed into the open end of the sleeve 3. Duringthis insertion of the connecting piece 4 the open end of the sleeve 3 isdeformed from having a circular appearance into an oval appearance, i.e.when the diameter connecting the inward protrusions is increased thediameter perpendicular thereto will be decreased. The not deformedsleeve must be designed to fit over the connecting piece with a playallowing this decrease.

To prevent the needle unit from wriggling due to the space between theouter wall of the connecting piece and the inner wall of the sleeve, anumber of spacer ribs 9 are provide on the inner wall of the sleeve 3.These ribs will keep the connecting piece 4 centred in the sleeve 3.

In FIG. 3 the needle unit is seen from the open end of the sleeve. Theradius of the connecting piece is indicated by a circle 16 which isformed by an edge of a guide at the inner end of the sleeve, into whichguide the end of the connecting piece fits. Axial spacer ribs 9 areprovided on the inner wall of the sleeve at both sides of the inwardprotrusions 6 but leaving the zones 90° displaced from the inwardprotrusions free to be pressed axially inwards until it contacts thewall of the connection piece. As indicated in FIG. 2, ribs 18 are alsoprovided extending longitudinally in the sleeve from the inwardprotrusions to said guide at the inner end of the sleeve. During theexertion of the radial pressure at the said zones the spacer ribs 9 abutthe connecting piece and act as fulcrums assisting the lifting of theinward protrusions 6 out of engagement with the recess 7 of theconnecting piece.

When it is wanted to dismount the needle unit from the connecting piece,radial inward pressures may by two fingers be imparted on the outer sideof the sleeve at said zones to disconnect the snap engagement betweenthe inward protrusions 6 and the recess 7 of the connecting piece.Therefore it is necessary that marks on he outer side of the sleeveindicate the position of such zones or indicate the positions of theinward protrusions.

In the embodiment shown in the FIGS. 1-3 such marks are provided asoutward protrusions 8 on the outer wall of the sleeve 3. Theseprotrusions have another function which will be described below.

When a new and unused the needle unit is stored in a magazine as shownin FIGS. 4 and 5, the hub with its sleeve is supported in a compartment10 into which it fits with a play allowing the necessary deformation ofthe sleeve 3. The inner space of the compartment conforms the outercontour of the hub 2, i.e. longitudinal recesses are provided in theinner wall of the compartment to accommodate the outward protrusions 8on the sleeve 3. The needle is protected by a needle cap 11 integralwith the compartment 10.

To mount a new needle unit on a syringe, the user may grasp the magazinewith the unit with one hand without any risk of scratching himself bythe needle. With his other hand he may grasp the syringe and insert theconnecting piece of this syringe into the open end of the sleeve, theopen end of which faces an open access end of the compartment of themagazine. The connection piece 4 is now pressed into the sleeve untilthe inward protrusions 6 of this sleeve snap into the recess 7 of thisconnection piece. The needle unit may now be drawn out of the magazineby the syringe.

When a used needle unit shall be disposed of, this needle unit mountedon the syringe is reinserted in the magazine but in a rotationalposition wherein the outward protrusions 8 of the sleeve 3 are notaccommodated in the recesses 12. Thereby the outward protrusions 8 willabut a reinforcement 13 in the compartment and will be pressed radiallyinwards. As the outward protrusions of the sleeve are provided at thezones at which a radially inward pressure will deform the sleeve in away bringing the inward protrusions of this sleeve out of engagementwith the recesses of the connection piece, the needle unit will bedisconnected from the syringe. As the outward protrusions of the sleeveare pressed into the reinforced part of the compartment, the unit willbe wedged in this part and will not follow the syringe when it isretracted. A remounting of the needle unit is not possible as the sleeveremains in a deformed condition so that the inward protrusion of thesleeve will not engage the recesses of the connecting part if this partis reinserted in the sleeve. FIGS. 12 and 13 shows the described needleunit wedged into the magazine for final deposition.

To ensure that the sleeve 3 and not the compartment 10 is deformed, whenthe used needle unit is wedged into this compartment, the compartmentwall is reinforced by the provision of the part 13 having an enlargedwall thickness. As another reinforcing feature helping the compartment10 to keep its cylindric shape, a flange 17 is provided surrounding theaccess opening of the compartment. The flange 17 may further act as asupport for a closure. This closure may be a foil 19 sealed along theflange 17 to enable a sterile storage of the unused needle unit.

FIG. 6 shows another embodiment of a needle unit seen from the open endof the sleeve. This embodiment differs from the one shown in FIG. 6 bythe positions of the inward protrusions 6 being indicated bylongitudinal grooves 14 in the outer surface of the sleeve 3. FIGS. 7and 8 shows this unit stored in a magazine having a compartment 10, aneedle cap 11, and a flange 17 as has the magazine of FIGS. 4 and 5. Therecesses 12 of the magazine of FIGS. 4 and 5 are in FIGS. 7 and 8replaced by longitudinal ribs 15 which are accommodated in the grooves14 of the needle unit when this needle unit is new and stored in themagazine. When a used needle unit is reinserted in the magazine it shallbe rotated with its grooves 14 displaced 90° from the ribs 15 of thecompartment. The ribs 15 will then exert the radial inward pressures onthe sleeve 3 which are necessary to disengage the inward protrusions 6of this sleeve from the recess 7 of the connecting piece. FIGS. 14 and15 shows a needle unit of the kind just described wedged into itsmagazine for final deposition.

It shall be noticed that by embodiments wherein the inward pressures areprovided by ribs in the compartment, the used needle unit must bereinserted into the compartment in a rotational position by which it isensured that the ribs acts at the zones designed for being the objectsof radially inward pressures. In embodiments using outward protrusionson the sleeve of the needle unit it is inherently ensured that pressuresexerted by the protrusions abutting elements in the compartment areexerted at the zones carrying the outward protrusions. The only demandas to the rotational position when reinserted is that this position mustdiffer from the position of the original storage with the outwardprotrusions accommodated in recesses.

Elements of the FIGS. 6, 7, and 8 which corresponds to the elements ofthe embodiment described in FIGS. 1-5 are given the same referencenumerals.

FIGS. 9, 10, and 11 shows still another embodiment for a needle unit andthe magazine for its storage and final deposition wherein three inwardprotrusions 6 are provided on the sleeve 3 at 120° intervals along theinner periphery thereof. Outward protrusions 8 are provided at the zoneswhere radially inward pressures must be exerted to release the snapengagement between the needle unit and a syringe. Spacer ribs 9 areprovided in pairs at both sides of each inward protrusion leaving zonesfor exertion of radially inward pressures to deform the sleeve. Thecompartment of the magazine for storage of the new needle unit has threerecesses for accommodating the outward protrusions 8 of the needle unit.

In FIGS. 16 and 17 it is shown how a used needle unit of this kind iswedged into the magazine for final deposition.

It appears that the needle unit will always be either mounted on asyringe or stored or disposed of in a magazine.

I claim:
 1. In combination a magazine and a removable needleunit,wherein said needle unit comprises a needle mounted in a hub and asleeve made from a deformable material surrounding an end of the needleat a distance from said needle, said sleeve including at least onesnap-lock element designed to engage a cooperating element on the outletend of a syringe for securing said needle unit on the syringe, andwherein said sleeve includes specific zones, spaced from said at leastone snap-lock member, which when pressed radially inwardly deform saidsleeve in a manner such that the locking engagement between said sleeveand the syringe outlet end is released; and wherein said magazinecomprises a compartment for accommodating said needle unit in aplurality of rotational positions; and wherein said needle unit andmagazine further include a syringe/needle unit release means which doesnot press said zones radially inwardly in a first rotational position ofsaid needle unit, such that the needle unit may lock onto a syringeoutlet end, and which presses said zones radially inwardly in a secondrotational position of said needle unit, thereby causing said needleunit to release from a syringe outlet end.
 2. A magazine and needle unitaccording to claim 1, wherein said syringe/needle unit release meanscomprises protrusions provided on the needle hub at said zones and areinforcement part in said magazine which engages said protrusions insaid second rotational position to press said zones inwardly, and whichincludes recesses to receive said protrusions in said first rotationalposition so as not to press said zones inwardly.
 3. A magazine andneedle unit according to claim 2, wherein said compartment has an accessopening and is reinforced against deformation by a flange surroundingsaid opening.
 4. A magazine and needle unit according to claim 3,wherein said flange and said compartment are one integral plasticmember.
 5. A magazine and needle unit according to claim 4, furthercomprising a removable foil fixed to the flange surrounding said openingfor sealing said compartment.
 6. A magazine and needle unit according toclaim 3, further comprising a removable foil fixed to the flangesurrounding said opening for sealing said compartment.
 7. A magazine andneedle unit according to claim 1, wherein said syringe/needle unitrelease means comprises a plurality of axial ribs on an inner wall ofsaid magazine which press said specific zones inwardly in said secondrotational position, and wherein said sleeve includes a plurality ofaxial recesses for receiving said ribs in said first rotational positionso as not to press said zones inwardly.
 8. A magazine and needle unitaccording to claim 7, wherein said compartment has an access opening andis reinforced against deformation by a flange surrounding said opening.9. A magazine and needle unit according to claim 8, wherein said flangeand said compartment are one integral plastic member.
 10. A magazine andneedle unit according to claim 9, further comprising a removable foilfixed to the flange surrounding said opening for sealing saidcompartment.
 11. A magazine and needle unit according to claim 8,further comprising a removable foil fixed to the flange surrounding saidopening for sealing said compartment.
 12. A magazine and needle unitaccording to claim 1, wherein said compartment has an access opening andis reinforced against deformation by a flange surrounding said opening.13. A magazine and needle unit according to claim 12, wherein saidflange and said compartment are one integral plastic member.
 14. Amagazine and needle unit according to claim 13, further comprising aremovable foil fixed to the flange surrounding said opening for sealingsaid compartment.
 15. A magazine and needle unit according to claim 12,further comprising a removable foil fixed to the flange surrounding saidopening for sealing said compartment.